Horses used to pull barges along canals using tow ropes.
Today’s invention resurrects this approach in applying it to shipping.
Instead of horses, think remote-controlled anchor subs.
Ships in a fleet would do away with onboard main engines, motors, propellers and all that stuff.
Instead, they would be equipped with a number of small submersibles. Each of these would descend to the sea floor, ship-lengths ahead, trailing an anchor chain.
The subs would actively seek suitable purchase sites, attach themselves to rocks/crevices and then a set of winches on board ship would wind the chains in -driving the vessel forward.
Advantages of this method include: 1. Much less subsea noise and thus less disturbance to ocean life. 2. Potentially much higher accelerations than can be achieved using normal propellers or thrusters. 3. Greater operational flexibility via swapping subs. 4. Cheaper ships.